中文摘要：

2004年CINRAD／SA雷达新的冰雹探测算法（HDA）代替了原来的算法，新的冰雹探测算法（HDA）估测任意尺寸的冰雹概率（POH）、直径大于等于19mm的强冰雹概率（POSH）和最大冰雹直径预测（MEHS）。结合济南雷达探测资料对冰雹探测算法预测效果进行了检验，虽然有较高的探测准确率，但同时错误率较高，临界成功率较低，最大冰雹尺寸预测值与实况的平均差值约为14．6mm。对2002～2005年济南雷达站的历史资料进行了统计分析，降雹单体和非降雹单体在最大反射率因子上存在较大差异，5、6、7月的降雹单体最大反射率因子平均值分别为59．7、61．8、63．9dBz，非降雹单体最大反射率因子平均值分别为53．8、54．9、55．6dBz。依据统计数据，对冰雹探测算法中的反射率因子等门限值调整为53dBz后，冰雹预测仍具有较高的探测准确率，错误率和临界成功率得到了明显改善；对最大冰雹尺寸预测中的算法因子门限值调整后，预测值与实况有较好的对应关系。

英文摘要：

An enhanced hail detection algorithm （HDA） for the CINRAD/SA radar replaced the original hail algorithm in 2004. The new HDA can estimate the probability of hail （POH, any size）, severe hail （diameter greater that 19 ram）, and expected maximumize hail for each detected storm cell. The performance of POH detection is evaluated with Jinan＇ s CINRAD/SA data, using 50 % as the warning threshold for the POH param- eter, and the verification against hail observations of any size is conducted, and the following accuracy measures are obtained： POD （Probability Of Detection） is 100%, FAR （Falas Alarm Ratio） is 72.2% ,CSI （Critical Success Index） is 88 %. The expected maximum hail size is 14.6 mm bigger than the actual maximum hail size averagely. Using Jinan-CINRAD/SA data of 2001 to 2005, the distributive characteristics of the maximum reflectivity in the cases of convective clouds are analyzed. The maximum reflectivities are 59.7, 61.8, 63.9 dBz for hailstorms and53.8, 54.9, 55.6 dBz for non-hail storms in May, June and July, respectively. So the minimum and maximum reflectivities of a component used in the calculation of the probability of hail are modulated from 45 to 53 dBz, and FAR and CSI are improved obviously. Through adjusting three parameters computing the expected maximum hail size, the expected maximum hail size is close to the actual one.